code: def idx_to_class(idx):
      idx = idx % 6
      if idx < 2:
          return str(idx + 1)
      elif idx < 5:
          return "3"
      else:
          return "4"
  
file_path: pykale/tests/loaddata/test_sampler.py
imports: import itertools
  from collections import Counter
  import numpy
  from kale.loaddata.sampler import BalancedBatchSampler, ReweightedBatchSampler
label_desc: Use image node_id 1 for calling a global function with example usage: idx_to_class(idx) and returns: str, str, str